Last accessed network information by terminating Wi-Fi calling device

ABSTRACT

The systems, devices, and methods discussed herein are directed to a Wi-Fi calling (WFC) portable communication device, or a user equipment (UE), for providing information regarding a cellular network that a terminating WFC UE has last accessed. In response to receiving a call in a wireless local area network (WLAN), the terminating WFC UE transmits the information regarding the last accessed cellular network, such as radio access technology and radio cell identity to a service provider.

BACKGROUND

Modern telecommunication systems include heterogeneous mixtures ofsecond, third, and fourth generation (2G, 3G, and 4G) cellular-wirelessaccess technologies, which can be cross-compatible and can operatecollectively to provide data communication services. Global Systems forMobile (GSM) is an example of 2G telecommunications technologies;Universal Mobile Telecommunications System (UMTS) is an example of 3Gtelecommunications technologies; and Long Term Evolution (LTE),including LTE Advanced, and Evolved High-Speed Packet Access (HSPA+) areexamples of 4G telecommunications technologies. The 5G telecommunicationtechnologies are the next generation mobile networks that are designedto combine both an evolution and revolution of the existing LTE/LTE-Amobile networks to provide a much higher connectivity, greaterthroughput, much lower latency, and ultra-high reliability to supportnew use cases and applications.

In addition, a new generation of portable communication devices, or userequipment (UE), are capable of making phone calls over a wireless localarea network (WLAN), referred as Wi-Fi™ calling or WFC. To be able tomake or receive a call through a WLAN, the UE first registers itsInternet Protocol (IP) address with the WLAN. When the UE makes a Wi-Ficall (the UE is now an originating WFC UE), information regarding a lastaccessed cellular network by the originating WFC UE is provided to aservice provider. However, when the UE receives a Wi-Fi call (the UE isnow a terminating WFC UE), the terminating WFC UE does not provide theinformation regarding its last accessed cellular network to the serviceprovider.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is set forth with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Theuse of the same reference numbers in different figures indicates similaror identical items or features.

FIG. 1 illustrates an example environment in which a portablecommunication device, or user equipment (UE), accesses services via awireless local area network (WLAN).

FIG. 2 illustrates an example process for the UE to provide lastaccessed network information to a service provider.

FIG. 3 illustrates an example block diagram of the UE.

FIG. 4 illustrates an example environment in which multiple UEs accessservices via different WLANs.

FIG. 5 illustrates an example process for a mobile network operator(MNO) to analyze network performance in the example environment of FIG.4 based on the example process illustrated in FIG. 2.

DETAILED DESCRIPTION

The systems, devices, and methods discussed herein are directed to aWi-Fi calling (WFC) portable communication device, or a user equipment(UE), for providing information regarding a last accessed network, suchas radio access technology, radio cell identity, and location of acellular network that the WFC UE had accessed, to a service providerupon receiving a call in a wireless local area network (WLAN). Forexample, the WFC UE may receive a SIP INVITE message while registered inthe WLAN, and in response, may send a 183 message, which includes theinformation regarding the last cellular network that the WFC UE hadaccessed, to the service provider, or a mobile network owner (MNO) ofthe WFC UE.

The MNO may collect last accessed network information from a pluralityof WFC UEs, both originating WFC UEs and terminating WFC UEs, group theWFC UEs based on network identities included in the last accessednetwork information, calculate a number of WFC UEs for each networkidentity, and analyze the performance of each network based, at least inpart, on the number of the WFC UEs. The performance analyzed may includekey performance indicators, such as a UE-originated call success rate, adrop call rate, registrations success rate, and the like.

The systems, devices, and methods described herein can be implemented ina number of ways. Example implementations are provided below withreference to the following figures.

FIG. 1 illustrates an example environment 100 in which a portablecommunication device, or user equipment (UE), 102 accesses services viaa wireless local area network (WLAN) 104.

The UE 102 may be implemented as any suitable mobile computing devicesconfigured to communicate over a wireless network, including, withoutlimitation, a mobile phone (e.g., a smart phone), a tablet computer, alaptop computer, a portable digital assistant (PDA), a wearable computer(e.g., electronic/smart glasses, a smart watch, fitness trackers, etc.),a networked digital camera, and/or similar mobile devices. In thissense, the terms “communication device,” “wireless device,” “mobiledevice,” “computing device,” and “user equipment” may be usedinterchangeably herein to describe any communication device capable ofperforming the techniques described herein. Furthermore, the UE 102, aswell as the trusted and untrusted Radio Access Networks (RANs), may becapable of communicating over wirelessly using any suitable wirelesscommunications/data technology, protocol, or standard, such as GlobalSystem for Mobile Communications (GSM), Time Division Multiple Access(TDMA), Universal Mobile Telecommunications System (UMTS),Evolution-Data Optimized (EVDO), Long Term Evolution (LTE), Advanced LTE(LTE+), Generic Access Network (GAN), Unlicensed Mobile Access (UMA),Code Division Multiple Access (CDMA), Orthogonal Frequency DivisionMultiple Access (OFDM), General Packet Radio Service (GPRS), EnhancedData GSM Environment (EDGE), Advanced Mobile Phone System (AMPS), HighSpeed Packet Access (HSPA), evolved HSPA (HSPA+), Voice over IP (VoIP),Voice over LTE (VoLTE), IEEE 802.1x protocols, WiMAX, Wi-Fi, and/or anyfuture IP-based network technology or evolution of an existing IP-basednetwork technology.

The WLAN 104 comprises N access points (AP) 106 of which three (106(1),106(2), and 106(N)) are shown, a WLAN gateway (GW) 108 communicativelycoupled to the AP 106, and an authentication, authorization, accounting(AAA) server 110 communicatively coupled to the WLAN GW 108. The AP 106is a transceiver that connects a WLAN device, such as the UE 102, to theWLAN. The WLAN GW 108 routes data packets from the AP 106 to othernetwork and vice versa. The AAA server 110 tracks user activities byauthenticating the user with unique identifying information, authorizingthe user to access the network and services, and accounting, ortracking, the activities of the user. The AAA server 110 may beconnected other servers via Internet 112. The WLAN 104 iscommunicatively coupled to a WLAN service provider 114 which providesservices accessible through APs 106 to devices registered with the WLAN104. The WLAN service provider 114 comprises an enhanced access networkquality protocol (E-ANQP) server 116, which WLAN devices, such as the UE102, use to perform network discovery. The UE 102 is capable ofestablishing communication with a WLAN, such as the WLAN 104, and with acellular network, such as a cellular network 118, which may be a networkof a mobile network operator (MNO) 120 of the UE 102, MNO network 122.The MNO network 122 comprises an evolved packet data gateway (ePDG) 124,an enhanced access network discovery and selection function (E-ANDSF)server 126, and a home location register/home subscriber server(HLR/HSS) 128. The ePDG 124 enables secure connection between the UE 102and the MNO network 122. The E-ANDSF server 126 assists the UE 102 indiscovering WLANs and provides the UE 102 with rules and policies forconnecting to the WLANs. The HLR/HSS 128 stores and updates the usersubscription information, and also generates security information.

As the UE 102 successfully registers with the WLAN 104, the UE 102maintains information regarding the last cellular network it hadaccessed, such as the cellular network 118. The UE 102 may maintain thelast accessed network information for a predetermined time period, twohours for example. When the UE 102 initiates a call through the WLAN104, the UE 102 provides the last accessed network information as a partof the call initiation, for example, the last accessed networkinformation may be included in a SIP INVITE message. When the UE 102receives a call through the WLAN 104, for example, the UE 102 mayreceive a SIP INVITE message, then in response, UE 102 may send the lastaccessed network information, for example, in a 183 message, to the MNO120.

FIG. 2 illustrates an example process 200 for the UE 102 to provide lastaccessed network information to a service provider, such as the MNO 120.

In block 202, the UE 102 may register with a WLAN, such as the WLAN 104.In block 204, the UE 102 may receive a call through the WLAN 104, forexample, the UE 102 may receive a SIP INVITE message. In response toreceiving the SIP INVITE, the UE 102, in block 206, may transmit lastaccessed network information, such as information regarding the cellularnetwork 118, to a service provider, such as the MNO 120. The UE 102 maytransmit the last accessed network information included in a 183 messageto the MNO 120 in response to receiving the SIP INVITE message. The UE102 may transmit the last accessed network information to the MNO 120while the call is being established.

The last accessed network information may include information, such asan identity, a location, and supported cellular technologies, associatedwith a cellular network, such as the cellular network 118, that the UE102 had accessed immediately prior to registering with the WLAN 104.

The UE 102 may receive a service associated with the last accessednetwork information from the MNO 120, in block 208. The serviceassociated with the last accessed network information may be based on aperformance analysis of the cellular network 118 conducted by the MNO120, and may be associated with a key performance indicator, such as aUE-originated call success rate, a drop call rate, or a registrationsuccess rate of the cellular network 118.

The UE 102 may maintain the last accessed network information for apredetermined period of time. For example, the cellular networkassociated with last accessed network information may be a cellularnetwork that the UE 102 had accessed within the predetermined period oftime, such as two hours, immediately prior to registering with the WLAN104. If the UE 102 had not accessed a cellular network within thepredetermined period of time prior to registering with the WLAN 104,then the last accessed network information may be set to a null value.For example, the UE 102 may be turned off and be turn back on after someperiod time in a WLAN only environment, and if the predetermined periodof time were set to be two hours, and the UE 102 last accessed thecellular network three hours prior to registering with the WLAN 104,then the last accessed network information might be considered stale.The last accessed network information might then be deleted, be set to anull value, be kept but assigned a null value, or be kept but the UE 102might refrain from sending it.

FIG. 3 illustrates an example block diagram 300 of the UE 102. The UE102 comprises one or more processors 302, a WLAN transceiver 304communicatively coupled to the one or more processors 302, and acellular transceiver 306. The one or more processors 302 may be directlyor indirectly coupled to other components and/or modules of the UE 102.In some embodiments, the one or more processors 302 may be a centralprocessing unit (CPU), a graphics processing unit (GPU), or both CPU andGPU, or other processing unit or component known in the art. The WLANtransceiver 304 may be configured to establish communication between theUE 102 and a WLAN, such as the WLAN 104 described above, using a WLANspecific communication method such as 802.11 family of standards and thelike. The cellular transceiver 306 is configured to establishcommunication between the UE 102 and a cellular network, such as thecellular network 118 described above, using a cellular network specificcommunication method or standard such as GSM, UNITS, LTE, 5G standardsand the like. The UE 102 further comprises an input/output (I/O)interface 308, a battery 310, and memory 312, each communicable coupledthe one or more processors 302 and may be directly or indirectly coupledto other components and/or modules of the UE 102. The I/O interface 308may include a keyboard, mouse, touch pad, touch screen, microphone, andthe like, configured to receive an input from a user and may alsoinclude a speaker, display which may be a touchscreen, and the like,configured to provide an output for the user. The battery 310 mayprovide power to all components and modules of the UE 102 requiringpower. Memory 312 may include volatile memory (such as random accessmemory (RAM)) and/or non-volatile memory (such as read-only memory(ROM), flash memory, etc.). Memory 312 may also include additionalremovable storage and/or non-removable storage including, but notlimited to, flash memory, magnetic storage, optical storage, and/or tapestorage that may provide non-volatile storage of computer-readableinstructions, data structures, program modules, and other data for theUE 102.

Memory 312, a non-transitory computer storage medium, may storecomputer-readable instructions executable by the one or more processors302, that when executed by the one or more processors 302, cause the oneor more processors 302 to perform operations described above withreferenced to FIG. 2. For example, the UE 102 may, via the WLANtransceiver 304, register with a WLAN, such as the WLAN 104, receive acall through the WLAN 104, and in response to receiving the call,transmitting last accessed network information of the UE 102 to the MNO120. The last accessed network information may include informationassociated with a cellular network, such as the cellular network 118,that the UE 102 has last accessed via the cellular transceiver 306 priorto registering with the WLAN 104. The UE 102 may receive the callthrough the WLAN 104 by receiving a SIP INVITE message, and transmit thelast accessed network information of the UE 102 by transmitting the lastaccessed network information in a SIP 183 message. The UE 102 maytransmit the SIP 183 message including the last accessed networkinformation while the call is being set up.

As discussed above with referenced to FIG. 2, the UE 102 may maintainthe last accessed network information for a predetermined period oftime. For example, the cellular network associated with last accessednetwork information may be a cellular network that the UE 102 hadaccessed within the predetermined period of time, such as two hours,immediately prior to registering with the WLAN 104. If the UE 102 hadnot accessed a cellular network within the predetermined period of time,then the last accessed network information may be set to a null value.For example, if the predetermined period of time were set to be twohours, and the UE 102 last accessed the cellular network three hoursprior to registering with the WLAN 104, then the last accessed networkinformation might be considered stale. The last accessed networkinformation might then be deleted, be set to a null value, be kept butassigned a null value, or be kept but the UE 102 might refrain fromsending it.

As discussed above with reference to FIG. 2, the information associatedwith the cellular network 118 that the UE 102 had last accessed mayinclude an identity, a location, and supported cellular technologies ofthe cellular network 118. The UE 102 may receive a service associatedwith the last accessed network information from the MNO 120 based onanalysis of key performance indicators of the cellular network 118conducted by the MNO 120, and may be associated with a UE-originatedcall success rate, a drop call rate, and a registration success rate ofthe cellular network 118.

FIG. 4 illustrates an example environment 400 in which multiple UEsaccess services via different WLANs. Similar to the environmentdiscussed above with reference to FIG. 1, the example environment 400illustrates UEs having accessed cellular networks prior to registeringwith WLANs, and each component illustrated in FIG. 4 may includecomponents and functions as described above with reference to FIGS. 1and 2.

Multiple UEs, of which three (UEs 102, 402, and 404) are shown, areregistered with the WLAN 104, having accessed the cellular network 118of the MNO 120 prior to registering with the WLAN 104. Similarly, twoother sets of multiple UEs, of which three for each set (UEs 406, 408,and 410, and UEs 412, 414, and 416) are shown, are registered with WLANs418 and 420, respectively, having accessed cellular networks 422 or 424of the MNO 120 prior to registering with the WLANs 418 and 420. In thisexample, prior to registering with the WLAN 418, the UE 406 isillustrated to have accessed the cellular network 118, the UE 408 isillustrated to have accessed the cellular network 422, and the UE 410 isillustrated to have accessed the cellular network 424. The UE 412 isillustrated to have accessed the cellular network 422, and the UEs 414and 416 are illustrated to have accessed the cellular network 424 priorto registering with the WLAN 420.

FIG. 5 illustrates an example process 500 for the MNO 120 to analyzenetwork performance in the example environment 400 based on the exampleprocess illustrated in FIG. 2.

In block 502, the MNO 120 may receive last accessed network informationfrom a plurality of originating WFC UEs. For example, the UE 102registered with the WLAN 104, the UEs 406 and 408 with registered withthe WLAN 418, and the UE 412 registered with the WLAN 420 may initiate,or originate, calls via the respective WLANs, and may transmit therespective last accessed network information to the MNO 120. Asdiscussed above with reference to FIGS. 2 and 3, last accessed networkinformation may include an identity, a location, and supported cellulartechnologies of the cellular network last accessed by a UE prior toregistering with a WLAN. The MNO 120 may receive the last accessednetwork information in SIP INVITE messages transmitted by theoriginating WFC UEs 102, 406, 408, and 412.

The MNO 120, at block 504, may group the originating WFC UEs based onnetwork identities included in corresponding last accessed networkinformation from the originating WFC UEs. In this example, the UEs 102and 406 are grouped under the cellular network 118, the UE 408 isgrouped under the cellular network 422, and the UE 412 is also groupedunder the cellular network 422 based on network identities included inthe respective last accessed network information.

In block 506, the MNO 120 may receive last accessed network informationfrom a plurality of terminating WFC UEs. For example, the UEs 402 and404 registered with the WLAN 104, the UE 410 with registered with theWLAN 418, and the UEs 414 and 416 registered with the WLAN 420 mayreceive calls via the respective WLANs, and may, in response toreceiving the calls, transmit the respective last accessed networkinformation to the MNO 120. The MNO 120 may receive the last accessednetwork information in SIP 183 messages transmitted by the terminatingWFC UEs 402, 404, 410, 414, and 416 in response to the terminating WFCUEs 402, 404, 410, 414, and 416 receiving SIP INVITE messages.

The MNO 120, at block 508, may group the terminating WFC UEs based onnetwork identities included in corresponding last accessed networkinformation from the terminating WFC UEs. In this example, the UEs 402and 404 are grouped under the cellular network 118, the UE 410 isgrouped under the cellular network 424, and the UEs 414 and 416 aregrouped also under the cellular network 424 based on network identitiesincluded in the respective last accessed network information.

In block 510, the MNO 120 may calculate a total number of WFC UEs percellular network based on the network identity. In this example, thereare four UEs (UEs 102, 402, 404, and 406) under the cellular network118, two UEs (UEs 408 and 412) under the cellular network 422, and threeUEs (UEs 410, 414, and 416) under the cellular network 424. The MNO 120,in block 512 may analyze performance of each cellular network based, atleast in part, on the total number of WFC UEs associated with thenetwork. The performance analyzed may include key performanceindicators, such as a UE-originated call success rate, a drop call rate,or a registration success rate.

Alternatively, or additionally, after grouping the originating WFC UEsbased on the network identities in block 504, the MNO 120 may calculatethe total number of originating WFC UEs per cellular network based onthe network identity, and analyze performance of each cellular networkbased, at least in part, on the total number of the originating WFC UEsassociated with the network. The MNO 120 may also calculate the totalnumber of terminating WFC UEs per cellular network based on the networkidentity after grouping the terminating WFC UEs based on networkidentities in block 508, and analyze performance of each cellularnetwork based, at least in part, on the total number of the terminatingWFC UEs associated with the network.

Some or all operations of the methods described above can be performedby execution of computer-readable instructions stored on acomputer-readable storage medium, as defined below. The term“computer-readable instructions” as used in the description and claims,include routines, applications, application modules, program modules,programs, components, data structures, algorithms, and the like.Computer-readable instructions can be implemented on various systemconfigurations, including single-processor or multiprocessor systems,minicomputers, mainframe computers, personal computers, hand-heldcomputing devices, microprocessor-based, programmable consumerelectronics, combinations thereof, and the like.

Memory 312, discussed above with referenced to FIG. 3, is an example ofcomputer-readable media. Computer-readable media includes at least twotypes of computer-readable media, namely computer storage media andcommunications media. Computer storage media includes volatile andnon-volatile, removable and non-removable media implemented in anyprocess or technology for storage of information such ascomputer-readable instructions, data structures, program modules, orother data. Computer storage media includes, but is not limited to,phase change memory (PRAM), static random-access memory (SRAM), dynamicrandom-access memory (DRAM), other types of random-access memory (RAM),read-only memory (ROM), electrically erasable programmable read-onlymemory (EEPROM), flash memory or other memory technology, compact diskread-only memory (CD-ROM), digital versatile disks (DVD) or otheroptical storage, magnetic cassettes, magnetic tape, magnetic diskstorage or other magnetic storage devices, or any other non-transmissionmedium that can be used to store information for access by a computingdevice. In contrast, communication media may embody computer-readableinstructions, data structures, program modules, or other data in amodulated data signal, such as a carrier wave, or other transmissionmechanism. As defined herein, computer storage media does not includecommunication media.

The computer-executable instructions stored on one or morecomputer-readable storage media that, when executed by one or moreprocessors, perform operations described above with reference to FIGS.2, 3, and 5. Generally, computer-executable instructions includeroutines, programs, objects, components, data structures, and the likethat perform particular functions or implement particular abstract datatypes. The order in which the operations are described is not intendedto be construed as a limitation, and any number of the describedoperations can be combined in any order and/or in parallel to implementthe processes.

Conclusion

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described. Rather,the specific features and acts are disclosed as exemplary forms ofimplementing the claims.

What is claimed is:
 1. A method in a user equipment (UE) comprising:registering with a wireless local area network (WLAN); receiving a callthrough the WLAN; and in response to receiving the call, transmittingover the WLAN, in a SIP 183 message, last accessed network informationof the UE and a location of the last accessed network to a serviceprovider associated with the WLAN, wherein the last accessed networkinformation includes information associated with a cellular network thatthe UE has last accessed prior to registering with the WLAN and the lastaccessed network information is a null value upon determining that theUE has not accessed any cellular network within the predetermined periodof time prior to registering with the WLAN, wherein the cellular networkand the WLAN are different networks, the cellular network utilizinglicensed spectrum and the WLAN utilizing unlicensed spectrum.
 2. Amethod of claim 1, wherein the service provider is a mobile networkoperator (MNO) of the UE.
 3. A method of claim 1, wherein theinformation associated with the cellular network that the UE has lastaccessed includes: an identity of the cellular network, and informationregarding cellular technologies supported by the cellular network.
 4. Amethod of claim 3, further comprising: receiving a service associatedwith the last accessed network information from the service provider. 5.A method of claim 4, wherein the service associated with the lastaccessed network information is based on a performance analysis of thecellular network conducted by the service provider associated with atleast one of: a UE-originated call success rate, a drop call rate, or aregistration success rate.
 6. A method of claim 4, wherein the serviceassociated with the last accessed network information is based on aperformance analysis of the cellular network conducted by the serviceprovider associated a UE-originated call success rate.
 7. A method ofclaim 1, wherein the last accessed network information is a null valueupon determining that the UE has not accessed any cellular networkwithin the predetermined period of time prior to registering with theWLAN.
 8. A method of claim 1, wherein transmitting the last accessednetwork information of the UE comprises: transmitting the last accessednetwork information while the call is being established.
 9. A method ofclaim 1, wherein receiving the call through the WLAN includes receivinga SIP INVITE message.
 10. The method of claim 1, wherein the cellularnetwork that the UE has last accessed is a cellular network the UE haslast accessed within a predetermined period of time prior to registeringwith the WLAN.
 11. A user equipment (UE) comprising: one or moreprocessors; a wireless local area network (WLAN) transceiver coupled tothe one or more processors; a cellular transceiver coupled to the one ormore processors; and memory coupled to the one or more processors; thememory storing computer-readable instructions executable by the one ormore processors, that when executed by the one or more processors, causethe one or more processors to perform operations comprising: registeringwith a WLAN via the WLAN transceiver; receiving a call through the WLAN;and in response to receiving the call through the WLAN, transmitting, ina SIP 183 message via the WLAN, last accessed network information of theUE to a service provider associated with the WLAN, the last accessednetwork information including information associated with a cellularnetwork that the UE has last accessed via the cellular transceiver priorto registering with the WLAN, the information associated with a cellularnetwork that the UE has last accessed including a location of thecellular network and the last accessed network information is a nullvalue when the UE has not accessed any cellular network within thepredetermined period of time prior to registering with the WLAN, whereinthe cellular network and the WLAN are different networks, the cellularnetwork utilizing licensed spectrum and the WLAN utilizing unlicensedspectrum.
 12. A UE of claim 11, wherein the information associated withthe cellular network that the UE has last accessed includes: an identityof the cellular network, and information regarding cellular technologiessupported by the cellular network.
 13. A UE of claim 12, wherein theoperations further comprise: receiving a service associated with thelast accessed network information from the service provider based on aperformance analysis of the cellular network conducted by the serviceprovider associated with at least one of: a UE-originated call successrate, a drop call rate, or a registration success rate.
 14. A UE ofclaim 11, wherein receiving the call through the WLAN includes receivinga SIP INVITE message.
 15. The UE of claim 11, wherein the cellularnetwork that the UE has last accessed is a cellular network the UE haslast accessed within a predetermined period of time prior to registeringwith the WLAN.
 16. A non-transitory computer-readable medium havingstored thereon programming instructions that, when executed by a userequipment (UE), cause the UE to perform operations comprising:registering with a wireless local area network (WLAN); receiving a callthrough the WLAN; and in response to receiving the call through theWLAN, transmitting, in a SIP 183 message, last accessed networkinformation of the UE to a service provider associated with the WLAN,wherein the last accessed network information includes informationassociated with a cellular network that the UE has last accessed priorto registering with the WLAN, the information associated with a cellularnetwork that the UE has last accessed including a location of thecellular network and the last accessed network information is a nullvalue when the UE has not accessed any cellular network within thepredetermined period of time prior to registering with the WLAN, whereinthe cellular network and the WLAN are different networks, the cellularnetwork utilizing licensed spectrum and the WLAN utilizing unlicensedspectrum.
 17. The non-transitory computer-readable medium of claim 16,wherein the last accessed network information associated with thecellular network that the UE has last accessed includes: an identity ofthe cellular network, and information regarding cellular technologiessupported by the cellular network.
 18. The non-transitorycomputer-readable medium of claim 17, wherein the operations furthercomprise: receiving a service associated with the last accessed networkinformation from the service provider based on a performance analysis ofthe cellular network conducted by the service provider associated withat least one of: a UE-originated call success rate, a drop call rate, ora registration success rate.
 19. The non-transitory computer-readablemedium of claim 16, wherein receiving the call through the WLAN includesreceiving a SIP INVITE message.
 20. The non-transitory computer-readablemedium of claim 16, wherein the cellular network that the UE has lastaccessed is a cellular network the UE has last accessed within apredetermined period of time prior to registering with the WLAN.